In the field of proteome analysis taking a primary role in post-genome researches, a combination of two-dimensional electrophoresis (2DE) and Western blotting is known as an excellent separation analysis method. The 2DE is capable of separating proteome into a plurality of components (proteins) with high resolution by employing various separation media on the basis of two independent physical properties (electric charge and molecular weight) that are specific to each protein. When further analyzing proteins by utilizing the separation result obtained with the 2DE, it is preferable to fixate plural proteins, which are contained in the separation medium, to a transfer film by the Western blotting. This is because the protein fixated to the transfer film can be preserved in a stable state for a long term and is easier to analyze. The Western blotting can be said as being an essential process particularly when biological features, such as an increase or decrease of expression and the presence or absence of posttranslational modification, of plural proteins are to be comparatively studied in an exhaustive manner by utilizing the separation result obtained with the 2DE.
Independent devices for the 2DE and the Western blotting have been employed up to date. This implies the necessity of operations of taking out the separation medium from an electrophoresis device after the electrophoresis, moving the separation medium into a transfer device, and setting a transfer film in the transfer device to perform a transfer process. When the manual operations by a researcher are interposed between the electrophoresis and the transfer as described above, a problem arises in that reproducibility of the obtained result reduces. Furthermore, because the separation medium to be handled is a very soft and breakable gel, expert skills are needed to carry out the Western blotting.
Meanwhile, regarding capillary electrophoresis (CE) using a capillary, Patent Literature (PTL) 1 proposes a technique for carrying out the electrophoresis and the transfer in one device. More specifically, the proposed technique can make a sample, which is discharged through a capillary (filled with a gel or a solution), adsorbed directly onto a transfer film and can recover the sample in one device. According to the proposed technique, the electrophoresis and the transfer can be performed continuously.